VISUAL PROGRAMMING_IT0309 Semester Number 05. G.SUJATHA & R.VIJAYALAKSHMI Assistant professor(o.g) SRM University, Kattankulathur

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1 School of Computing, 12/26/ VISUAL PROGRAMMING_IT0309 Semester Number 05 G.SUJATHA & R.VIJAYALAKSHMI Assistant professor(o.g) SRM University, Kattankulathur

2 School of Computing, Department 12/26/ Disclaimer The contents of the slides are solely for the purpose of teaching students at SRM University. All copyrights and Trademarks of organizations/persons apply even if not specified explicitly.

3 UNIT IV PROGRAMMING FOR THE INTERNET School of Computing, Department 12/26/2012 3

4 CONTENTS Introduction to ASP.NET Web Forms and Controls Data Binding and Data Source Controls Validation Controls Master and Content pages The Asp.Net Configuration Files and security Caching. School of Computing, Department 12/26/2012 4

5 School of Computing, Department 12/26/ INTRODUCTION TO ASP.NET Server side programming technology Consists of static HTML interspersed with script ASP intrinsic objects (Request, Response, Server, Application, Session) provide services Commonly uses ADO to interact with databases Application and session variables Application and session begin/end events ASP manages threads and database connections,

6 School of Computing, Department 12/26/ INTRODUCTION TO ASP.NET ASP.NET provides services to allow the creation, deployment, and execution of Web Applications and Web Services Like ASP, ASP.NET is a server side technology Web Applications are built using Web Forms Web Forms are designed to make building web based applications as easy as building Visual Basic applications

7 School of Computing, Department 12/26/ ASP.NET Overview Goals Simplify: less code, easier to create and maintain Multiple, compiled languages Fast Scalable Manageable Customizable and extensible Secure Tool support

8 School of Computing, Department 12/26/ ASP.NET Overview Key Features Web Forms Web Services Built on.net Framework Simple programming model Maintains page state Multibrowser support XML configuration Complete object model

9 School of Computing, Department 12/26/ ASP.NET Overview Key Features Session management Caching Debugging Extensibility Separation of code and UI Security ASPX, ASP side by side Simplified form validation Cookieless sessions

10 School of Computing, Department 12/26/ WEB FORM CONTROLS Web controls appear in HTML markup as namespaced tags Web controls have an asp: prefix <asp:button onclick="button1_click runat=server> <asp:textbox onchanged="text1_changed runat=server> Defined in the System.Web.UI.WebControls namespace This namespace is automatically mapped to the asp: prefix

11 School of Computing, Department 12/26/ WEB FORM CONTROLS Web Controls provide extensive properties to control display and format, e.g. Font BackColor, ForeColor BorderColor, BorderStyle, BorderWidth Style, CssClass Height, Width Visible, Enabled

12 School of Computing, Department 12/26/ WEB FORM CONTROLS Four types of Web Controls Intrinsic controls List controls Rich controls Validation controls

13 School of Computing, Department 12/26/ Intrinisic Controls Correspond to HTML controls Supported controls <asp:button> <asp:imagebutton> <asp:linkbutton> <asp:hyperlink> <asp:textbox> <asp:checkbox> <asp:radiobutton> <asp:image> <asp:label>

14 School of Computing, Department 12/26/ Intrinisic Controls TextBox, ListControl, CheckBox and their subclasses don t automatically do a postback when their controls are changed Specify AutoPostBack=true to make change events cause a postback

15 School of Computing, Department 12/26/ LIST CONTROLS Controls that handle repetition are asp:dropdownlist> <asp:listbox> <asp:radiobuttonlist> <asp:checkboxlist> <asp:repeater> asp:datalist> <asp:datagrid>

16 School of Computing, Department 12/26/ LIST CONTROLS Repeater, DataList and DataGrid controls Powerful, customizable list controls Expose templates for customization Can contain other controls Provide event bubbling through their OnItemCommand event More about these controls and templates later

17 School of Computing, Department 12/26/ CheckBoxList & RadioButtonList Provides a collection of check box or radio button controls Can be populated via data binding <asp:checkboxlist id=check1 runat="server"> <asp:listitem>item 1</asp:ListItem> <asp:listitem>item 2</asp:ListItem> <asp:listitem>item 3</asp:ListItem> <asp:listitem>item 4</asp:ListItem> <asp:listitem>item 5</asp:ListItem> </asp:checkboxlist>

18 School of Computing, Department 12/26/ Rich Controls Custom controls with rich functionality Supported Controls <asp:calendar> <asp:adrotator>

19 School of Computing, Department 12/26/ DATA SOURCE AND DATA BOUND CONTROLS Data Source Controls There are several new data source controls in ASP.NET 2.0, such as the SqlDataSource, ObjectDataSource, XmlDataSource, AccessDataSource, and SiteMapDataSource They all can be used to retrieve data from their respective types of data sources and can be bound to various data bound controls. SQL Data source control is used to retrieve the data from SQL database.

20 School of Computing, Department 12/26/ DATA SOURCE AND DATA BOUND CONTROLS DATA BINDING CONTROL Data bound Web server controls are controls that can be bound to a data source control to make it easy to display and modify data in your Web application» Grid view control It control displays data as a table and provides the capability to sort columns, page through data, and edit or delete a single record» Details View control It can bind to a set of results such as a table of employees containing each employee's name, address, job title, and so on.» FormView Control It renders a single record at a time from a data source and provides the capability to page through multiple records.

21 School of Computing, Department 12/26/ VALIDATION CONTROLS A Validation server control is used to validate the data of an input control. If the data does not pass validation, it will display an error message to the user. RequiredFieldValidator CompareValidator RangeValidator RegularExpressionValidator CustomValidator ValidationSummary

22 School of Computing, Department 12/26/ Common validator properties ControlToValidate Display ErrorMessage Text Enabled EnableClientScript ValidationGroup IsValid

23 School of Computing, Department 12/26/ Required Field Validator It Ensures that a value is entered EXAMPLE CODE <asp:textbox ID="txtName" runat="server"></asp:textbox> <asp:requiredfieldvalidator ID="RequiredFieldValidator1" runat="server" ControlToValidate="txtName" ErrorMessage="You must enter a name."> </asp:requiredfieldvalidator>

24 School of Computing, Department 12/26/ Compare Validator A compare validator compares the two value. EXAMPLE CODE <asp:comparevalidator ID="CompareValidator1" runat="server" ControlToValidate="txtQuantity" Type="Integer" Operator="GreaterThan" ValueToCompare="0" ErrorMessage="Quantity must be greater than zero."> </asp:comparevalidator

25 School of Computing, Department 12/26/ Range Validator A range validator that checks for a numeric range EXAMPLE CODE <asp:rangevalidator ID="RangeValidator1" runat="server" ControlToValidate="txtDays" Type="Integer" MinimumValue="1" MaximumValue="14" ErrorMessage="Days must be between 1 and 14."> </asp:rangevalidator>

26 School of Computing, Department 12/26/ Regular Expression Validator Ensures that the value of an input control matches a specified pattern EXAMPLE CODE <asp:regularexpressionvalidator runat="server" id="zipcodevalidator" ControlToValidate="ZipCodeTextBox" ErrorMessage="Invalid ZIP code format; format should be either or " ValidationExpression="(\d{5}( \d{4})?" />

27 School of Computing, Department 12/26/ Custom Validator and ValiDATION SUMMARY Custom validator lets you create custom client or server side validation function Validation summary control displays list of validation errors in one place

28 School of Computing, Department 12/26/ MASTER AND CONTENT PAGES Masters define common content and placeholders (<asp:contentplaceholder>) Content pages reference masters and fill placeholders with content (<asp:content>) ContentPlaceHolder controls can define content of their own ("default content") Default content is displayed ONLY if not overridden by content page

29 School of Computing, Department 12/26/ Creating Master page 1.Create a master page with.master extension 2. Define a master directive: <%@ master.. %> 3. Add content: I. Can contain any html or control page content II. Define replaceable place holder regions: Use an <asp:contentplaceholder> control Add default content within it (optional)

30 School of Computing, Department 12/26/ Using Master page 1.Create an ASP.NET page (.aspx extension) 2. On the page directive: page masterpagefile= %> attribute to reference master Set the title attribute Page title= jeff %> 3. Optionally add content to override the master: a. Only <asp:content> controls or server side script allowed b. <asp:content> controls replace regions in the master: The contentplaceholderid identifies master s region <asp:content> controls can contain any page content

31 School of Computing, Department 12/26/ Authentication The Windows Asp.NetAuthentication Configuration (via Files IIS) and security Basic, Digest, NTLM, Kerberos, Certificate Support Forms based (Cookie) Authentication Application credential verification Certificate Authentication Supports Microsoft Passport Authentication

32 School of Computing, Department 12/26/ Forms Based Authentication Easy to implement ASP.NET provides redirection Steps Configure IIS to allow anonymous users (typically) Configure ASP.NET cookie authentication Write your login page Secures not all Only Files with named extensions

33 School of Computing, Department 12/26/ Forms Authentication authentication mode= "Forms"> <forms name=".aspxauth" loginurl="login.aspx" protection="all" timeout="30" path="/" /> </authentication>

34 School of Computing, Department 12/26/ Authentication Using Windows Accounts Authenticate users with Windows user accounts by combining IIS authentication and the Windows authentication provider for ASP.NET No authentication specific code needs to be written with this approach ASP.NET constructs and attaches a WindowsPrincipal object to the application context

35 School of Computing, Department 12/26/ Certificate Authentication A certificate is a digital "key" installed on a computer Certificates can be mapped to user accounts Consider Certificate authentication when: Data is considered very sensitive and you require a very secure solution Mutual authentication is required Third parties will manage the relationship between the server and the certificate holder Client interaction must be seamless; for example, automated B2B exchanges

36 School of Computing, Department 12/26/ Certificate Authentication Do not use Certificate authentication when: The cost of issuing and managing client certificates outweighs the value of the added security Client certificates must be deployed to the client workstations Map certificates to: Individual user accounts (one to one mapping) Any user from a single company (many to one mapping)

37 School of Computing, Department 12/26/ Certificate Authentication Configure IIS for Certificate authentication Configure the ASP.NET Web.config file <!-- web.config file --> <system.web> <authentication mode="windows" /> </system.web>

38 School of Computing, Department 12/26/ Passport Authentication A centralized authentication service provided by Microsoft Consider Passport authentication when: Your site will interact with other Passport enabled sites Single sign on capability is required External maintenance of user names and passwords is useful Do not use Passport authentication when: You want to use user names and passwords already stored in your own database or Active Directory

39 School of Computing, Department 12/26/ Passport Authentication Requires registration with the Passport service and installation of the Passport SDK on the server Delegation is not possible on Windows 2000 Passport User ID (PUID) is an identity only Implement code to map PUID to users in Active Directory or custom database Passport uses encrypted cookies making system secure Combine Passport with SSL to prevent replay attacks for highest level of security

40 School of Computing, Department 12/26/ Passport Authentication Install Passport SDK on server Register with Passport service Configure IIS for Anonymous authentication Configure the ASP.NET Web.config file <!-- web.config file --> <system.web> <authentication mode="passport" /> </system.web>

41 School of Computing, Department 12/26/ CONFIGURATION FILES Web.Config Each Web.config file applies configuration settings to its own directory and all child directories below it. Configuration files in child directories can supply configuration information in addition to that inherited from parent directories, and the child directory configuration settings can override or modify settings defined in parent directories Machine.config The machine.config file is at the top of the hierarchy and its setting apply to all applications running on the machine.

42 School of Computing, Department 12/26/ CACHING Caching is the most critical factor in creating scalable, high performance Web applications Caching locations Web server, proxy server, and client browsers Types of caching Output caching Data caching

43 School of Computing, Department 12/26/ Output Caching What is output OutputCache directive and the cache object Output caching attributes: Duration Location VaryByParam VaryByHeader VaryByCustom

44 School of Computing, Department 12/26/ Output Caching Pages that use the output cache are executed one time, and the page results are cached The pre executed page is then served to later requests Performance and scalability both benefit Server response times reduced CPU load reduced Appropriate caching of pages affects site performance dramatically

45 School of Computing, Department 12/26/ Output OutputCache declaratively controls caching behavior For.aspx,.asmx, or.ascx The cache object programmatically controls caching behavior <%@ OutputCache Duration="600 Location="Any VaryByParm= none %> Is equivalent to Response.Cache.SetExpires(DateTime.Now.AddSeconds(600) ); Response.Cache.SetCacheability(HttpCacheability.Public );

46 School of Computing, Department 12/26/ Output Caching Duration sets the time to cache the output In seconds Required Location sets the location to cache the output Server: The output is held in memory on the Web server and is used to satisfy requests Downstream: A header is added to the response to indicate to proxy servers to cache the page Client: A header is added to the response indicating to browsers to cache the page Any: Output cache can be located on any of these locations None: No output caching is turned on for the item

47 School of Computing, Department 12/26/ Output Caching VaryByParam The cache stores multiple copies of a page based on specific Querystring or Form parameters and any combinations thereof VaryByHeader The cache stores multiple copies of a page based on HTTP headers VaryByCustom If the value is Browser, cache varies by browser type and major version If the value is a custom string, you must override HttpApplication.GetVaryByCustomString in the Global.asax and implement your own caching logic

48 Although similar to the familiar application variables model, it is much more powerful 12/26/2012 School of Computing, Department 48 Data Caching The data cache holds application data such as strings, datasets, and other objects Adding items to the data cache is easy Cache( Counter ) = Mycount.text

49 School of Computing, Department 12/26/ Data Caching Cache object features Dependencies allow logic to invalidate cached items Scavenging (automatic expiration) Callbacks when an item is removed

50 School of Computing, Department 12/26/ bibliography penguin.ewu.edu/cscd306 Core C# and.net, Stephen C.perry, Pearson Education

51 School of Computing, Department 12/26/ Review questions Differentiate ASP and ASP.Net List the web controls Create the On line registration form and validate all the fields using validation controls Explain in detail about application security and configuration files What are the data bound data source controls Differentiate master and content pages Explain in detail about caching Write the use of passport authentication

52 School of Computing, Department 12/26/ Review questions What is meant by certificate authentication Define ASP.Net forms List the type of ASP.Netn controls Differentiate data and output caching